1. Field of the Invention
This invention relates to novel solid electrolyte compositions and to electric current producing cells containing these compositions. More particularly, this invention relates to solid electrolyte compositions and to improvements in the electric current producing cells of the type comprising an alkali metal anode, a solid electrolyte, and a cathode having metal chalcogenide cathode-active material.
2. Description of the Prior Art
There has been considerable interest in recent years in developing high energy density batteries or voltaic cells. Among the systems being investigated are those employing nonaqueous liquid and fused electrolytes, light-weight metals, such as alkali metals, as anodes, and cathodes containing chalcogenide compounds, particularly transition metal chalcogenide compounds (see, for example, U.S. Pat. Nos. 3,925,098, 3,864,167 and 3,791,867).
Additionally, various efforts have been made to develop solid state electrolytes for electrochemical cell systems. Alkali metal-aluminum-halogen compounds have been utilized in liquid and molten state electrolyte systems (e.g. as described in U.S. Pat. No. 3,877,984 and U.S. Pat. No. 3,751,298) and solid alkali metal-aluminum-halogen compound conductivity studies have been made (for example, N. I. Anufrieva et al, Tseut. Metal., Vol. 1, pp 32-36 (1973); W. Weppner et al, Physics Letters, Vol. 58A, No. 4, pp 245-248(1976); and J. Schoonman et al, J. Solid State Chem., Vol. 16, pp 413-422 (1976)). Additionally, solid electrolytes containing mixtures of lithium sulfate and lithium halides have been proposed (see U.S. Pat. No. 3,506,490, for example). However, to date, there has been no suggestion that the lithium aluminum sulfate-containing compounds of the type employed in the present invention might be useful as solid state electrolytes or that they may be used in electrochemical cells having alkali metal anodes and chalcogenide cathodes.